#ifndef U2PixelUtil_H__
#define U2PixelUtil_H__

#include "U2PreRequest.h"
#include "U2MemoryAllocatorConfig.h"
#include "U2SharedPtr.h"
#include "U2ColourValue.h"
#include "U2Common.h"


U2EG_NAMESPACE_BEGIN

/** The pixel format used for images, textures, and render surfaces */
enum PixelFormat
{
    /// Unknown pixel format.
    PF_UNKNOWN              = 0,
    /// 8-bit pixel format, all bits luminace.
    PF_L8                   = 1,
	PF_BYTE_L               = PF_L8,
    /// 16-bit pixel format, all bits luminace.
    PF_L16                  = 2,
	PF_SHORT_L              = PF_L16,
    /// 8-bit pixel format, all bits alpha.
    PF_A8                   = 3,
	PF_BYTE_A               = PF_A8,
    /// 8-bit pixel format, 4 bits alpha, 4 bits luminance.
    PF_A4L4                 = 4,
	/// 2 byte pixel format, 1 byte luminance, 1 byte alpha
	PF_BYTE_LA              = 5,
    /// 16-bit pixel format, 5 bits red, 6 bits green, 5 bits blue.
    PF_R5G6B5               = 6,
	/// 16-bit pixel format, 5 bits red, 6 bits green, 5 bits blue.
    PF_B5G6R5               = 7,
    /// 8-bit pixel format, 2 bits blue, 3 bits green, 3 bits red.
    PF_R3G3B2               = 31,
    /// 16-bit pixel format, 4 bits for alpha, red, green and blue.
    PF_A4R4G4B4             = 8,
    /// 16-bit pixel format, 5 bits for blue, green, red and 1 for alpha.
    PF_A1R5G5B5             = 9,
    /// 24-bit pixel format, 8 bits for red, green and blue.
    PF_R8G8B8               = 10,
    /// 24-bit pixel format, 8 bits for blue, green and red.
    PF_B8G8R8               = 11,
    /// 32-bit pixel format, 8 bits for alpha, red, green and blue.
    PF_A8R8G8B8             = 12,
    /// 32-bit pixel format, 8 bits for blue, green, red and alpha.
    PF_A8B8G8R8             = 13,
    /// 32-bit pixel format, 8 bits for blue, green, red and alpha.
    PF_B8G8R8A8             = 14,
	/// 32-bit pixel format, 8 bits for red, green, blue and alpha.
	PF_R8G8B8A8             = 28,
    /// 32-bit pixel format, 8 bits for red, 8 bits for green, 8 bits for blue
    /// like PF_A8R8G8B8, but alpha will get discarded
    PF_X8R8G8B8             = 26,
    /// 32-bit pixel format, 8 bits for blue, 8 bits for green, 8 bits for red
    /// like PF_A8B8G8R8, but alpha will get discarded
    PF_X8B8G8R8             = 27,
#if U2_ENDIAN == U2_ENDIAN_BIG
	/// 3 byte pixel format, 1 byte for red, 1 byte for green, 1 byte for blue
	PF_BYTE_RGB             = PF_R8G8B8,
	/// 3 byte pixel format, 1 byte for blue, 1 byte for green, 1 byte for red
	PF_BYTE_BGR             = PF_B8G8R8,
	/// 4 byte pixel format, 1 byte for blue, 1 byte for green, 1 byte for red and one byte for alpha
	PF_BYTE_BGRA            = PF_B8G8R8A8,
	/// 4 byte pixel format, 1 byte for red, 1 byte for green, 1 byte for blue, and one byte for alpha
	PF_BYTE_RGBA            = PF_R8G8B8A8,
#else
	/// 3 byte pixel format, 1 byte for red, 1 byte for green, 1 byte for blue
	PF_BYTE_RGB             = PF_B8G8R8,
	/// 3 byte pixel format, 1 byte for blue, 1 byte for green, 1 byte for red
	PF_BYTE_BGR             = PF_R8G8B8,
	/// 4 byte pixel format, 1 byte for blue, 1 byte for green, 1 byte for red and one byte for alpha
	PF_BYTE_BGRA            = PF_A8R8G8B8,
	/// 4 byte pixel format, 1 byte for red, 1 byte for green, 1 byte for blue, and one byte for alpha
	PF_BYTE_RGBA            = PF_A8B8G8R8,
#endif        
    /// 32-bit pixel format, 2 bits for alpha, 10 bits for red, green and blue.
    PF_A2R10G10B10          = 15,
    /// 32-bit pixel format, 10 bits for blue, green and red, 2 bits for alpha.
    PF_A2B10G10R10          = 16,
    /// DDS (DirectDraw Surface) DXT1 format
    PF_DXT1                 = 17,
    /// DDS (DirectDraw Surface) DXT2 format
    PF_DXT2                 = 18,
    /// DDS (DirectDraw Surface) DXT3 format
    PF_DXT3                 = 19,
    /// DDS (DirectDraw Surface) DXT4 format
    PF_DXT4                 = 20,
    /// DDS (DirectDraw Surface) DXT5 format
    PF_DXT5                 = 21,
	// 16-bit pixel format, 16 bits (float) for red
    PF_FLOAT16_R            = 32,
    // 48-bit pixel format, 16 bits (float) for red, 16 bits (float) for green, 16 bits (float) for blue
    PF_FLOAT16_RGB          = 22,
    // 64-bit pixel format, 16 bits (float) for red, 16 bits (float) for green, 16 bits (float) for blue, 16 bits (float) for alpha
    PF_FLOAT16_RGBA         = 23,
	// 32-bit pixel format, 32 bits (float) for red
    PF_FLOAT32_R            = 33,
    // 96-bit pixel format, 32 bits (float) for red, 32 bits (float) for green, 32 bits (float) for blue
    PF_FLOAT32_RGB          = 24,
    // 128-bit pixel format, 32 bits (float) for red, 32 bits (float) for green, 32 bits (float) for blue, 32 bits (float) for alpha
    PF_FLOAT32_RGBA         = 25,
	// 32-bit, 2-channel s10e5 floating point pixel format, 16-bit green, 16-bit red
	PF_FLOAT16_GR           = 35,
	// 64-bit, 2-channel floating point pixel format, 32-bit green, 32-bit red
	PF_FLOAT32_GR           = 36,
	// Depth texture format
	PF_DEPTH                = 29,
	// 64-bit pixel format, 16 bits for red, green, blue and alpha
	PF_SHORT_RGBA           = 30,
	// 32-bit pixel format, 16-bit green, 16-bit red
	PF_SHORT_GR             = 34,
	// 48-bit pixel format, 16 bits for red, green and blue
	PF_SHORT_RGB            = 37,
    /// PVRTC (PowerVR) RGB 2 bpp
    PF_PVRTC_RGB2           = 38,
    /// PVRTC (PowerVR) RGBA 2 bpp
    PF_PVRTC_RGBA2          = 39,
    /// PVRTC (PowerVR) RGB 4 bpp
    PF_PVRTC_RGB4           = 40,
    /// PVRTC (PowerVR) RGBA 4 bpp
    PF_PVRTC_RGBA4          = 41,
	// Number of pixel formats currently defined
    PF_COUNT                = 42
};
typedef std::vector<PixelFormat> PixelFormatList;

/**
 * Flags defining some on/off properties of pixel formats
 */
enum PixelFormatFlags {
    // This format has an alpha channel
    PFF_HASALPHA        = 0x00000001,      
    // This format is compressed. This invalidates the values in elemBytes,
    // elemBits and the bit counts as these might not be fixed in a compressed format.
    PFF_COMPRESSED      = 0x00000002,
    // This is a floating point format
    PFF_FLOAT           = 0x00000004,         
    // This is a depth format (for depth textures)
    PFF_DEPTH           = 0x00000008,
    // Format is in native endian. Generally true for the 16, 24 and 32 bits
    // formats which can be represented as machine integers.
    PFF_NATIVEENDIAN    = 0x00000010,
    // This is an intensity format instead of a RGB one. The luminance
    // replaces R,G and B. (but not A)
    PFF_LUMINANCE       = 0x00000020
};

/** Pixel component format */
enum PixelComponentType
{
    PCT_BYTE        = 0,    /// Byte per component (8 bit fixed 0.0..1.0)
    PCT_SHORT       = 1,    /// Short per component (16 bit fixed 0.0..1.0))
    PCT_FLOAT16     = 2,    /// 16 bit float per component
    PCT_FLOAT32     = 3,    /// 32 bit float per component
    PCT_COUNT       = 4     /// Number of pixel types
};

/** A primitive describing a volume (3D), image (2D) or line (1D) of pixels in memory.
 	In case of a rectangle, depth must be 1. 
 	Pixels are stored as a succession of "depth" slices, each containing "height" rows of 
 	"width" pixels.
*/
class _U2Share U2PixelBox : public Box, public ImageAlloc {
public:
	/// Parameter constructor for setting the members manually
	U2PixelBox() {}
	~U2PixelBox() {}
	/** Constructor providing extents in the form of a Box object. This constructor
		assumes the pixel data is laid out consecutively in memory. (this
		means row after row, slice after slice, with no space in between)
		@param extents	    Extents of the region defined by data
		@param pixelFormat	Format of this buffer
		@param pixelData	Pointer to the actual data
	*/
	U2PixelBox(const Box &extents, PixelFormat pixelFormat, void *pixelData=0):
		Box(extents), data(pixelData), format(pixelFormat)
	{
		setConsecutive();
	}
	/** Constructor providing width, height and depth. This constructor
		assumes the pixel data is laid out consecutively in memory. (this
		means row after row, slice after slice, with no space in between)
		@param width	    Width of the region
		@param height	    Height of the region
		@param depth	    Depth of the region
		@param pixelFormat	Format of this buffer
		@param pixelData    Pointer to the actual data
	*/
	U2PixelBox(size_t width, size_t height, size_t depth, PixelFormat pixelFormat, void *pixelData=0):
		Box(0, 0, 0, width, height, depth),
		data(pixelData), format(pixelFormat)
	{
		setConsecutive();
	}
	
    /// The data pointer 
    void *data;
    /// The pixel format 
    PixelFormat format;
    /** Number of elements between the leftmost pixel of one row and the left
     	pixel of the next. This value must always be equal to getWidth() (consecutive) 
		for compressed formats.
    */
    size_t rowPitch;
    /** Number of elements between the top left pixel of one (depth) slice and 
     	the top left pixel of the next. This can be a negative value. Must be a multiple of
     	rowPitch. This value must always be equal to getWidth()*getHeight() (consecutive) 
		for compressed formats.
    */
    size_t slicePitch;
    
    /** Set the rowPitch and slicePitch so that the buffer is laid out consecutive 
     	in memory.
    */        
    void setConsecutive()
    {
        rowPitch = getWidth();
        slicePitch = getWidth()*getHeight();
    }
    /**	Get the number of elements between one past the rightmost pixel of 
     	one row and the leftmost pixel of the next row. (IE this is zero if rows
     	are consecutive).
    */
    size_t getRowSkip() const { return rowPitch - getWidth(); }
    /** Get the number of elements between one past the right bottom pixel of
     	one slice and the left top pixel of the next slice. (IE this is zero if slices
     	are consecutive).
    */
    size_t getSliceSkip() const { return slicePitch - (getHeight() * rowPitch); }

    /** Return whether this buffer is laid out consecutive in memory (ie the pitches
     	are equal to the dimensions)
    */        
    bool isConsecutive() const 
	{ 
		return rowPitch == getWidth() && slicePitch == getWidth()*getHeight(); 
	}
    /** Return the size (in bytes) this image would take if it was
    	laid out consecutive in memory
  	*/
  	size_t getConsecutiveSize() const;
  	/** Return a subvolume of this U2PixelBox.
  		@param def	Defines the bounds of the subregion to return
  		@returns	A pixel box describing the region and the data in it
  		@remarks	This function does not copy any data, it just returns
  			a U2PixelBox object with a data pointer pointing somewhere inside 
  			the data of object.
  		@throws	Exception(ERR_INVALIDPARAMS) if def is not fully contained
  	*/
  	U2PixelBox getSubVolume(const Box &def) const;
    
    /**
     * Get colour value from a certain location in the U2PixelBox. The z coordinate
     * is only valid for cubemaps and volume textures. This uses the first (largest)
     * mipmap.
     */
    U2ColourValue getColourAt(size_t x, size_t y, size_t z);

    /**
     * Set colour value at a certain location in the U2PixelBox. The z coordinate
     * is only valid for cubemaps and volume textures. This uses the first (largest)
     * mipmap.
     */
    void setColourAt(U2ColourValue const &cv, size_t x, size_t y, size_t z);
};


/**
 * Some utility functions for packing and unpacking pixel data
 */
class _U2Share U2PixelUtil {
public:
    /** Returns the size in bytes of an element of the given pixel format.
     @returns
           The size in bytes of an element. See Remarks.
     @remarks
           Passing PF_UNKNOWN will result in returning a size of 0 bytes.
    */
    static size_t getNumElemBytes( PixelFormat format );

    /** Returns the size in bits of an element of the given pixel format.
      @returns
           The size in bits of an element. See Remarks.
       @remarks
           Passing PF_UNKNOWN will result in returning a size of 0 bits.
    */
    static size_t getNumElemBits( PixelFormat format );

	/** Returns the size in memory of a region with the given extents and pixel
		format with consecutive memory layout.
		@param width
			The width of the area
		@param height
			The height of the area
		@param depth
			The depth of the area
		@param format
			The format of the area
	  	@returns
	  		The size in bytes
		@remarks
			In case that the format is non-compressed, this simply returns
			width*height*depth*U2PixelUtil::getNumElemBytes(format). In the compressed
			case, this does serious magic.
	*/
	static size_t getMemorySize(size_t width, size_t height, size_t depth, PixelFormat format);
	
    /** Returns the property flags for this pixel format
      @returns
           A bitfield combination of PFF_HASALPHA, PFF_ISCOMPRESSED,
           PFF_FLOAT, PFF_DEPTH, PFF_NATIVEENDIAN, PFF_LUMINANCE
      @remarks
           This replaces the seperate functions for formatHasAlpha, formatIsFloat, ...
    */
    static unsigned int getFlags( PixelFormat format );

    /** Shortcut method to determine if the format has an alpha component */
    static bool hasAlpha(PixelFormat format);
    /** Shortcut method to determine if the format is floating point */
    static bool isFloatingPoint(PixelFormat format);
    /** Shortcut method to determine if the format is compressed */
    static bool isCompressed(PixelFormat format);
    /** Shortcut method to determine if the format is a depth format. */
    static bool isDepth(PixelFormat format);
    /** Shortcut method to determine if the format is in native endian format. */
    static bool isNativeEndian(PixelFormat format);
    /** Shortcut method to determine if the format is a luminance format. */
    static bool isLuminance(PixelFormat format);
	
	/** Return wether a certain image extent is valid for this image format.
		@param width
			The width of the area
		@param height
			The height of the area
		@param depth
			The depth of the area
		@param format
			The format of the area
		@remarks For non-compressed formats, this is always true. For DXT formats,
		only sizes with a width and height multiple of 4 and depth 1 are allowed.
	*/
	static bool isValidExtent(size_t width, size_t height, size_t depth, PixelFormat format);

    /** Gives the number of bits (RGBA) for a format. See remarks.          
      @remarks      For non-colour formats (dxt, depth) this returns [0,0,0,0].
    */
    static void getBitDepths(PixelFormat format, int rgba[4]);

	/** Gives the masks for the R, G, B and A component
	  @note			Only valid for native endian formats
    */
    static void getBitMasks(PixelFormat format, u2uint32 rgba[4]);

	/** Gives the bit shifts for R, G, B and A component
	@note			Only valid for native endian formats
	*/
	static void getBitShifts(PixelFormat format, unsigned char rgba[4]);

    /** Gets the name of an image format
    */
    static U2String getFormatName(PixelFormat srcformat);

    /** Returns wether the format can be packed or unpacked with the packColour()
    and unpackColour() functions. This is generally not true for compressed and
    depth formats as they are special. It can only be true for formats with a
    fixed element size.
      @returns 
           true if yes, otherwise false
    */
    static bool isAccessible(PixelFormat srcformat);
    
    /** Returns the component type for a certain pixel format. Returns PCT_BYTE
        in case there is no clear component type like with compressed formats.
        This is one of PCT_BYTE, PCT_SHORT, PCT_FLOAT16, PCT_FLOAT32.
    */
    static PixelComponentType getComponentType(PixelFormat fmt);
    
    /** Returns the component count for a certain pixel format. Returns 3(no alpha) or 
        4 (has alpha) in case there is no clear component type like with compressed formats.
     */
    static size_t getComponentCount(PixelFormat fmt);

    /** Gets the format from given name.
        @param  name            The string of format name
        @param  accessibleOnly  If true, non-accessible format will treat as invalid format,
                                otherwise, all supported format are valid.
        @param  caseSensitive   Should be set true if string match should use case sensitivity.
        @returns                The format match the format name, or PF_UNKNOWN if is invalid name.
    */
    static PixelFormat getFormatFromName(const U2String& name, bool accessibleOnly = false, bool caseSensitive = false);

    /** Gets the BNF expression of the pixel-formats.
        @note                   The string returned by this function is intented to use as a BNF expression
                                to work with Compiler2Pass.
        @param  accessibleOnly  If true, only accessible pixel format will take into account, otherwise all
                                pixel formats list in PixelFormat enumeration will being returned.
        @returns                A string contains the BNF expression.
    */
    static U2String getBNFExpressionOfPixelFormats(bool accessibleOnly = false);

    /** Returns the similar format but acoording with given bit depths.
        @param fmt      The original foamt.
        @param integerBits Preferred bit depth (pixel bits) for integer pixel format.
                        Available values: 0, 16 and 32, where 0 (the default) means as it is.
        @param floatBits Preferred bit depth (channel bits) for float pixel format.
                        Available values: 0, 16 and 32, where 0 (the default) means as it is.
        @returns        The format that similar original format with bit depth according
                        with preferred bit depth, or original format if no convertion occuring.
    */
    static PixelFormat getFormatForBitDepths(PixelFormat fmt, u2ushort integerBits, u2ushort floatBits);

    /** Pack a colour value to memory
    	@param colour	The colour
    	@param pf		Pixelformat in which to write the colour
    	@param dest		Destination memory location
    */
    static void packColour(const U2ColourValue &colour, const PixelFormat pf,  void* dest);
    /** Pack a colour value to memory
    	@param r,g,b,a	The four colour components, range 0x00 to 0xFF
    	@param pf		Pixelformat in which to write the colour
    	@param dest		Destination memory location
    */
    static void packColour(const u2uint8 r, const u2uint8 g, const u2uint8 b, const u2uint8 a, const PixelFormat pf,  void* dest);
     /** Pack a colour value to memory
    	@param r,g,b,a	The four colour components, range 0.0f to 1.0f
    					(an exception to this case exists for floating point pixel
    					formats, which don't clamp to 0.0f..1.0f)
    	@param pf		Pixelformat in which to write the colour
    	@param dest		Destination memory location
    */
    static void packColour(const float r, const float g, const float b, const float a, const PixelFormat pf,  void* dest);

    /** Unpack a colour value from memory
    	@param colour	The colour is returned here
    	@param pf		Pixelformat in which to read the colour
    	@param src		Source memory location
    */
    static void unpackColour(U2ColourValue *colour, PixelFormat pf,  const void* src);
    /** Unpack a colour value from memory
    	@param r,g,b,a	The colour is returned here (as byte)
    	@param pf		Pixelformat in which to read the colour
    	@param src		Source memory location
    	@remarks 	This function returns the colour components in 8 bit precision,
    		this will lose precision when coming from PF_A2R10G10B10 or floating
    		point formats.  
    */
    static void unpackColour(u2uint8 *r, u2uint8 *g, u2uint8 *b, u2uint8 *a, PixelFormat pf,  const void* src);
    /** Unpack a colour value from memory
    	@param r,g,b,a	The colour is returned here (as float)
    	@param pf		Pixelformat in which to read the colour
    	@param src		Source memory location
    */
    static void unpackColour(float *r, float *g, float *b, float *a, PixelFormat pf,  const void* src); 
    
    /** Convert consecutive pixels from one format to another. No dithering or filtering is being done. 
     	Converting from RGB to luminance takes the R channel.  In case the source and destination format match,
     	just a copy is done.
     	@param	src			Pointer to source region
     	@param	srcFormat	Pixel format of source region
     	@param   dst			Pointer to destination region
     	@param	dstFormat	Pixel format of destination region
     */
    static void bulkPixelConversion(void *src, PixelFormat srcFormat, void *dest, PixelFormat dstFormat, unsigned int count);

  	/** Convert pixels from one format to another. No dithering or filtering is being done. Converting
      	from RGB to luminance takes the R channel. 
	 	@param	src			U2PixelBox containing the source pixels, pitches and format
	 	@param	dst			U2PixelBox containing the destination pixels, pitches and format
	 	@remarks The source and destination boxes must have the same
     	dimensions. In case the source and destination format match, a plain copy is done.
    */
    static void bulkPixelConversion(const U2PixelBox &src, const U2PixelBox &dst);
};

U2EG_NAMESPACE_END

#endif